After a summer of healthcare battles and sliding approval ratings for President Obama, the White House is facing a troubling new trend: The voters losing faith in the president are the ones he had worked hardest to attract.

New surveys show steep declines in Obama’s approval ratings among whites — including Democrats and independents — who were crucial elements of the diverse coalition that helped elect the country’s first black president.

Among white Democrats, Obama’s job approval rating has dropped 11 points since his 100-days mark in April, according to surveys by the Pew Research Center for the People and the Press. It has dropped by 9 points among white independents and whites over 50, and by 12 points among white women — all groups that will be targeted by both parties in next year’s midterm elections.

“While Obama has a lock on African Americans, his support among white voters seems to be almost in a free fall,” said veteran Republican pollster Neil Newhouse.